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The molecular structures of ethyl 5-amino-3-(4,6-dimethylpyrimidin-2-ylamino)-1-methyl-1H-pyrazole-4-carboxylate, C13H18N6O2, (I), and ethyl 5-amino-3-(4,6-dimethylpyrimidin-2-ylamino)-1-(2-nitrophenylsulfonyl)-1H-pyrazole-4-carboxylate, C18H19N7O6S, (II), have been determined. There are two intramolecular N—H…O bonds and one intermolecular N—H…O hydrogen bond in (I). The rings formed by the N—H…O hydrogen bonds are almost planar. In (II), three intramolecular N—H…O hydrogen bonds exist. [ABSTRACT FROM AUTHOR]

Reactions of a series of unsymmetrically substituted N-heterocyclic carbene ligands with Ru3(CO)12afforded a variety of mononuclear (1, 2), trinuclear (3, 4, 5, and 5′), and tetranuclear (6, 7) ruthenium complexes via intramolecular ruthenium-mediated sp2and sp3C–H bond activations. Complexes 6and 7include an octahedral cluster skeleton consisting of four ruthenium atoms and two metalated carbon atoms. The formation of this type of ruthenium clusters is proposed to involve the initial C–C double-bond migration and subsequent sp2C–H bond activations. All new complexes were fully characterized, and the molecular structures of 1, 2, 5, 6, and 7were determined by X-ray diffraction analysis. [ABSTRACT FROM AUTHOR]

Thermal treatment of dihydrooctamethyl-s-indacene with Ru3(CO)12afforded the trinuclear and tetranuclear complexes Ru3(η5:η5:η2-C20H24)(CO)7(1) and Ru4(η5:η4:η1-C20H24)(μ-CO)2(CO)7(2), via intramolecular sp3C−H bond activation, and the mononuclear complex Ru(η5-C20H25)(CO)2Cl (3), which might be formed via chlorination of a terminal hydride complex during column chromatography. Reaction of 1,2,3,4,7-pentamethylindene with Ru3(CO)12also yielded the tetranuclear complex Ru4(η5:η3:η2-C14H16)(CO)9(4) via the same sp3C−H bond activation, together with the dinuclear complex [(η5-C9H2Me5)Ru(CO)]2(μ-CO)2(5). In contrast, reaction of 4,7-dimethylindene with Ru3(CO)12gave only the dinuclear complex [(η5-C9H5Me2)Ru(CO)]2(μ-CO)2(6). The molecular structures of all six complexes have been determined by single-crystal X-ray diffraction analysis. [ABSTRACT FROM AUTHOR]

Six robust intermetallic compounds with cations in three different tunnel-like structures have been synthesized in alkali-metal-Au-In systems via high-temperature solid-state methods and characterized by X-ray diffraction: AAu4-In6 [A = K (I), Rb (II), P6m2, Z = 1], K1.76(6)Au6In4 (III, I4/mcm, Z = 4), and AxAu2In2 [x ≈ 0.7, A = K (IV), Rb (V), Cs (VI), P42/nmc, Z = 8]. The first type is constructed from a single cage unit: an alkali-metal-centered 21-vertex polyhedron A@Au9In12 with 6-9-6 arrangement of planar rings. The others contain uniaxial arrays of tunnels built of differently puckered eight- and four-member Au/In rings. The largely different cation distributions depend on the tunnel constitutions and cation sizes. Tight-binding electronic structure calculations by linear muffin-tin-orbital (LMTO) methods were performed for I and idealized III in order to help understand their chemical bonding. These also reveal large differences in relativistic effects for Au d orbitals, as well as for different Au sites in each structure. [ABSTRACT FROM AUTHOR]